在Python的开发过程中，有时候会用到多线程的技术，例如在开发服务端程序时就不可避免的要使用多线程。
thread是相对低级的线程模块，threading是经过封装的功能比较强。
[codesyntax lang="python"]
__author__ = 'suren'
import thread
import time
def task():
print(1)
pass
thread.start_new_thread(task, ())
thread.start_new_thread(task, ())
time.sleep(3)
[/codesyntax]
线程模块thread中启动线程的函数，需要至少两个参数：函数名、函数的参数列表。
[codesyntax lang="python"]
__author__ = 'suren'
import threading
import time
class Task(threading.Thread):
def __init__(self):
threading.Thread.__init__(self)
pass
def run(self):
print('task thread started.')
pass
thread1 = Task()
thread2 = Task()
thread1.start()
thread2.start()
time.sleep(3)
[/codesyntax]
threading.Thread类中包含的函数有：
run()，线程启动时调用的代码
getName(),获取线程对象名称
setName()，设置线程对象名称
start()，启动线程的函数
join([timeout])，等待另一个线程运行结束后在调用
setDaemon(bool)，设置子线程是否随着主线程一起结束，必须在start之前调用
isDaemon()，检查是否为守护线程
isAlive()，检查线程是否还在运行中
[codesyntax lang="python"]
__author__ = 'suren'
import thread
import time
suren_lock = thread.allocate_lock()
num = 0
def task():
global num
while True:
try:
suren_lock.acquire()
num += 1
time.sleep(0.1)
print('task running : %d' % (num))
finally:
suren_lock.release()
pass
thread.start_new_thread(task, ())
thread.start_new_thread(task, ())
thread.start_new_thread(task, ())
thread.start_new_thread(task, ())
thread.start_new_thread(task, ())
time.sleep(1)
[/codesyntax]
上面的代码中，如果把获取、释放锁的行注释掉再运行的话，你会发现每次打印出的内容都是不一样的。
[codesyntax lang="python"]
__author__ = 'suren'
import threading
import time
suren_lock = threading.RLock()
num = 0
class Task(threading.Thread):
def __init__(self):
threading.Thread.__init__(self)
pass
def run(self):
global num
while True:
try:
suren_lock.acquire()
num += 1
time.sleep(0.1)
print('task running : %d' % (num))
pass
finally:
suren_lock.release()
pass
pass
thread1 = Task()
thread2 = Task()
thread3 = Task()
thread4 = Task()
thread5 = Task()
thread1.start()
thread2.start()
thread3.start()
thread4.start()
thread5.start()
time.sleep(1)
[/codesyntax]
同样地，要是把上面代码中获取、释放锁的行注释掉的话，打印出来的内容是乱的。
[codesyntax lang="python"]
__author__ = 'suren'
import threading
import time
condition = threading.Condition()
num = 0
class Producer(threading.Thread):
def __init__(self):
global num
while True:
try:
if num > 0:
condition.wait()
else:
time.sleep(0.1)
pass
finally:
condition.release()
pass
pass
class Consumer(threading.Thread):
def __init__(self):
threading.Thread.__init__(self)
pass
def run(self):
global num
while True:
try:
condition.acquire()
if num <= 0:
condition.wait()
else:
print('num : %d' % (num))
num -= 1
condition.notify()
time.sleep(0.3)
pass
finally:
condition.release()
pass
pass
producer1 = Producer()
consumer1 = Consumer()
consumer2 = Consumer()
consumer3 = Consumer()
consumer4 = Consumer()
producer1.start()
consumer1.start()
consumer2.start()
consumer3.start()
consumer4.start()
time.sleep(1)
[/codesyntax]
[codesyntax lang="python"]
__author__ = 'suren'
import threading
import time
from Queue import Queue
class Producer(threading.Thread):
def __init__(self, queue):
threading.Thread.__init__(self)
self.data = queue
pass
def run(self):
while True:
self.data.put(1)
time.sleep(0.1)
pass
class Consumer(threading.Thread):
def __init__(self, queue):
threading.Thread.__init__(self)
self.data = queue
pass
def run(self):
while True:
self.data.get()
print(self.data.qsize())
pass
queue = Queue()
producer1 = Producer(queue)
producer2 = Producer(queue)
producer3 = Producer(queue)
producer4 = Producer(queue)
consumer = Consumer(queue)
producer1.start()
producer2.start()
producer3.start()
producer4.start()
consumer.start()
time.sleep(1)
[/codesyntax]
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www.python.org/doc/2.5.2/lib/module-threading.html
